1. Field of the Invention
This invention relates to optical fiber splices for the repair of optical communication cable and particularly to a removable support structure in a housing for holding and aligning the fibers to be spliced.
2. Description of the Prior Art
The alignment and splicing of optical fibers has been accomplished in the past utilizing such devices as described in a publication entitled "A Low Loss Single Fiber Connector Alignment Guide" by Malcolm H. Hodge in the 1978 Fiber Optics Conference Proceedings, pp. 111-115, and in U.S. Pat. No. 4,257,674, entitled "Elastomeric Fiber Optic Splice", issued Mar. 24, 1981. The described tubular alignment guide includes four fused glass rods having elbows at opposite ends and internal vee-grooves formed by the cusps within the rods. Optical fibers inserted into opposite ends are bent into engagement along a common groove surface to align the fiber ends. Proper cleaving of the fiber ends and a silicone fluid within the guide at the interface minimize optical insertion losses. The alignment guide, however, does not provide protection, and requires careful threading for insertion of the fibers into the small tubular structure.
The splice assembly of the above-noted patent utilizes another guide having two mating longitudinal inserts of an elastomeric material within an outer sleeve. One insert has an inner groove along its length and the other a flat surface which together preferably form a triangular-shaped opening. Insertion of the fibers expands the walls of the opening to force the inserts against the sleeve. A slide and cam at each end of the housing position and bend the fiber for insertion into the central guide, and strain relief members secure the fibers at the outer ends. After the two opposing fibers are aligned, the cams are unlocked and the top lid of the housing snapped in place. This structure does not secure and position cable strength members and jacket as well as the fibers, does not retain the splice ends since the cams are released to avoid microbending losses, and the slide is not mechanically restrained. Insertion of the fibers into the alignment guide may also require careful manipulation.
Another housing for an optical fiber cable splice has been described in a paper presented at an August 1982 SPIE International Technical Symposium, entitled "Repair of Fiber Optic Cable in the Field," by M. H. Hodge, J. G. Woods, J. F. Larkin, and C. E. Loscoe, the latter two being the present inventors. This paper concerns a fiber optic splicing system utilizing a manually operated splicing machine in conjunction with a housing having recesses for directly receiving various preassembled splice components. This structure, however, does not permit mounting the elements in a separate removable support device for facilitating insertion of the fibers into the alignment guide and for retaining the spliced fibers in position.